JPH07272217A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To obtain a thin-film magnetic head of low-impedance noise. CONSTITUTION:This thin-film magnetic head is formed by successively laminating a lower core 4, an intermediate core 9 and an upper core 12 on a substrate 1 and spirally patterning and forming conductors 7 between the upper and lower cores 4 and 12 so as to pass part thereof. The conductors 7 formed in the outside regions between these upper and lower cores 4 and 12 is formed to a thickness larger than the thickness of the conductors 7 formed in the inside regions between the upper and lower cores 4 and 12, by which the impedance noise is lowered without increasing the number of turns even if there is restriction on the thickness between the upper and lower cores.

Description

Detailed Description of the Invention

[0001]

[0001]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head suitable for use in a magnetic recording / reproducing apparatus such as a magnetic disk.

[0003]

[0002]

[0004]

2. Description of the Related Art FIG. 12 is a schematic partial cross-sectional perspective view of a magnetic head used for a disk-shaped recording medium proposed by the present applicant (Japanese Patent Laid-Open No. 4-89609), and FIG. 13 is a core portion and a coil pattern. FIG. 3A is a schematic perspective view, FIG. 3B is a plan view, and FIG. 3C is a cross-sectional view taken along the line AA ′ of FIG.

In these figures, 1 is a substrate, 2 is an insulating layer, and 4 is a lower core made of a soft magnetic material. Reference numeral 5 denotes an insulating layer, and the coil conductor 7 is wound and embedded in the insulating layer 5. Reference numeral 9 is an intermediate core, 10 and 11 are insulating layers, and 12 is an upper core.

[0006]

G is a gap and 13 is the coil conductor 7.
And a lead portion 14 is continuously formed on the conductor 13. Reference numeral 15 denotes a pad portion, on the upper surface side of which an alloy layer 16 is provided, and a lead wire 17 is pressure-bonded to the alloy layer 16 to form one head element.

According to the head having such a structure, a head suitable for recording / reproducing with a narrow track or a narrow pitch can be obtained.

[0008]

[0004]

[0009]

However, in the structure described above, the cross sectional area of the coil conductor is small and the direct current resistance is large. Therefore, impedance noise is large, and the heat generated in the coil due to energization at the time of recording is large, and the members around the coil are distorted or cracked by heat, resulting in poor reliability.

[0010]

To solve this, the number of turns of the coil may be reduced or the cross-sectional area of the coil may be increased to reduce heat generation and impedance noise of the coil.
When the number of turns of the coil is reduced, the reproduction output is reduced and the recording current must be increased.

[0011]

If the horizontal width per winding is increased and the cross-sectional area is increased without reducing the number of turns, the magnetic path length (the distance between the front magnetic gap portion and the rear magnetic gap portion) becomes longer, The magnetic resistance increases and the recording / reproducing efficiency lowers.

[0012]

Further, it is possible to increase the thickness of the intermediate core in the vertical direction, but the thickness of the intermediate core may be limited due to circumstances such as obtaining a desired frequency.

Therefore, the present invention is to eliminate such problems and provide a reliable thin-film magnetic head with less impedance noise.

[0014]

[0008]

[0015]

In order to solve the above-mentioned problems, the thin-film magnetic head of the present invention comprises the following means.

That is, a lower core and an upper core are sequentially laminated on a substrate, and a part of the core is passed between the cores to form a spiral pattern of a conductor outside the cores. In the thin film magnetic head, the thin film magnetic head is characterized in that the thickness of the conductor formed by patterning between the cores is made thicker than the thickness of the conductor passing between the upper and lower cores. head.

[0017]

[0009]

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the thin film magnetic head of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic partial sectional perspective view of a thin film magnetic head according to the embodiment, FIG. 2 is a diagram showing only a core portion and a coil pattern, (A) is a schematic perspective view, and (B) is a diagram. A plan view and (C) are cross-sectional views taken along the line A-A 'of (B). The same components as those of the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

[0020]

In these figures, 1 is a substrate, 2 is an insulating layer, and 4 is a lower core made of a soft magnetic material, which is formed with a thickness of about 1 to 9 μm. Intermediate cores 9 and 9 having substantially the same thickness are provided on the front and rear portions of the upper surface of the lower core 4, and the upper core 12 is formed on the upper surfaces with the insulating layers 5 and 10 interposed therebetween. .

[0021]

Reference numeral 7 is a coil conductor, and a spiral pattern is formed so as to wind the intermediate core 9 on the rear side. The coil conductor 7 has a height sufficiently low to be embedded in the insulating layer 5 in the region between the cores, and the height is different in the outer region between the cores, and the insulating layer 2 further below the insulating layer 5 has a different height. Has reached about twice the height between the cores.

..

A conductor 13 is connected to the coil conductor 7 and is continuous with the lead portion 14 via the insulating layers 10 and 11. Reference numeral 15 denotes a pad portion, on the upper surface side of which an alloy layer 16 is provided, and a lead wire 17 is pressure-bonded to the alloy layer 16 to form one head element.

[0023]

Next, a method of manufacturing the thin film magnetic head having the above structure will be described with reference to FIGS.
In these figures, (A) shows a schematic sectional view and (B) shows a schematic partial plan view.

[0024]

First step (FIG. 3) A soft magnetic film containing Fe, Co, and Ni as main components is formed on the substrate 1, and a lower core 4 is formed by a photolithography process and ion milling.
To form. In addition, in order to avoid complexity, the substrate 1 is not shown in FIG. It is also omitted in each of the subsequent drawings (B).

[0025]

Second step (FIG. 4) An insulating layer 2 made of SiO ₂ , TiO ₂ , Al ₂ O ₃ or the like is formed to be thicker than the thickness of the lower core 4 by sputtering, vapor deposition, ion plating or the like, and a polishing step. Etc. to form a flat surface.

[0026]

Third step (FIG. 5) A groove is formed in the insulating layer 2 in a circular shape by a photolithography step, an etching step, etc., a conductor film of Cu or the like is formed in the groove by evaporation, etc., and is flattened by polishing to form a coil. The lower layer side of the conductor 7.

[0027]

Fourth Step (FIG. 6) A non-magnetic layer 8 made of SiO ₂ , TiO ₂ or the like to form a magnetic gap G is formed on the upper surface of the lower core, leaving a portion where the intermediate core 9 on the rear side is formed, Similar to the first step, the intermediate cores 9, 9 of the soft magnetic film containing Fe, Co, and Ni as the main components are formed on the upper surface at predetermined intervals.

Then, the insulating layer 5 is formed on the other portions where the intermediate cores 9 and 9 are left.

[0029]

Fifth Step (FIG. 7) A spiral groove 7a is formed on the upper surface side corresponding to the coil conductor 7 already formed on the lower layer side and the upper surface side on the lower core 4 by a photolithography process and an etching process. . Particularly, the groove 7a is formed so as not to reach the upper surface of the lower core 4 at the upper surface position of the lower core 4.

[0030]

Sixth Step (FIG. 8) A groove 7a in which the lower coil conductor 7 is formed is further formed so as to reach the coil conductor 7 by a photolithography process and an etching process, and the same as the third process. A conductor film such as Cu is formed on the entire area of the groove 7a.

[0031]

Seventh step (FIG. 9) An insulating layer 10 made of SiO ₂ , TiO _2, Al ₂ O ₃ or the like is formed on the portion excluding the intermediate cores 9, 9.

[0032]

Eighth step (FIG. 10) An upper core 12 is formed on the intermediate cores 9 and 9 and the insulating layer 10 in the upper surface region corresponding to the lower core 4 in the same manner as in the first step.

The insulating layer 1 is left with the upper core 12 left.
1 is formed.

[0034]

Ninth step (FIG. 11) The insulating layers 10 and 11 are provided with a conductor 13 which is a contact hole.
And a lead portion 14 connected to the coil conductor 7 through the conductor 13 is formed as a Cu layer into a predetermined shape by etching.

Then, the magnetic gap G is cut from the cutting line B-B 'so that the end portion is formed, and as shown in FIG. 1, a pad portion 15, an alloy layer 16 and a lead wire 17 are sequentially provided to form a thin film. Complete the magnetic head.

[0036]

As described above, in the thin-film magnetic head of this embodiment, the height (thickness) of the coil conductor 7 in the region outside the core is approximately twice as high as the height (thickness) inside the core. Therefore, the cross-sectional area is almost doubled, and the resistance value in this area is approximately halved.

The ratio of the part of the coil conductor 7 embedded in the core to the whole coil conductor is about 10 to 30%, and the ratio of the part of the coil conductor 7 embedded is 1/4 of the entire coil conductor. If so, the coil conductor 7
The resistance value of is about 60% of the conventional value.

[0038]

Therefore, according to the thin film magnetic head of the present embodiment, even when the thickness of the intermediate core is limited,
A highly reliable thin film magnetic head with low impedance noise can be obtained.

[0039]

In this embodiment, the height of the coil conductor 7 is extended to the side of the insulating layer 2, but it may be extended to the side of the insulating layers 10 and 11 on the contrary. The resistance value may be reduced by extending the height on both sides thereof.

Further, in the magnetic head of the above-mentioned embodiment, the coil conductor 7 is a one-layer winding pattern, but it is naturally applicable to a two-layer winding pattern, and in that case. The coil conductor 7 of the first layer may be provided on the lower core layer side, and the coil conductor 7 of the second layer may be provided on the upper core layer side.

[0041]

[0026]

[0042]

According to the thin-film magnetic head of the present invention, impedance noise can be reduced without increasing the number of windings even when the thickness between the upper and lower cores is restricted, and high precision is achieved. Thus, a reliable thin film magnetic head can be provided.

[Brief description of drawings]

FIG. 1 is a schematic partial cross-sectional perspective view of a thin film magnetic head according to an embodiment of the present invention.

FIG. 2 is a view showing only a core portion and a coil pattern.

FIG. 3 is a diagram showing a first manufacturing process of the thin film magnetic head according to the embodiment of the invention.

FIG. 4 is a diagram showing a second manufacturing process.

FIG. 5 is a diagram showing a third manufacturing process.

FIG. 6 is a diagram showing a fourth manufacturing process.

FIG. 7 is a diagram showing a fifth manufacturing process.

FIG. 8 is a diagram showing a sixth manufacturing process.

FIG. 9 is a diagram showing a seventh manufacturing process.

FIG. 10 is a diagram showing an eighth manufacturing process.

FIG. 11 is a diagram showing a ninth manufacturing process.

FIG. 12 is a schematic partial cross-sectional perspective view of a conventional thin film magnetic head.

FIG. 13 is a diagram showing only a core portion and a coil pattern in a conventional thin film magnetic head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2, 5, 10, 11 Insulating layer 4 Lower core 7 Coil conductor 9 Intermediate core 12 Upper core 14 Lead part 16 Alloy layer 17 Lead wire

Claims (1)

[Claims] 1. A lower core and an upper core are sequentially laminated on a substrate,
A thin film magnetic head formed by passing a part of these between the cores to form a spiral pattern of a conductor outside the cores, wherein a pattern is formed outside the cores. The thin-film magnetic head is characterized in that the thickness of the conductor to be formed is thicker than the thickness of the conductor passing between the upper and lower cores.